Auto headlight dimmer



Nov. 13, 1928. 1,691,832

J. C. SWEET AUTO HEADLIGHT DIMMER Filed Aug. 5, 1926 v Fgzi.

[NI 'EYTOR. 8 6.601066,

Patented Nov. 13, 1928.

UNITED STATES PATENT OFFICE.

runs 0. SWEET, or rLm'r, monrean, ASSIGNOR or ONE-HALF T IDA n. swnnr, or

. FLINI, MICHIGAN.

AUTO HEADLIGHT DIMMER.

Application filed August 5,

This invention relates to an illuminating device and pertains particularly to an incandescent electric light.

' The primary object of this invention is the provision, in a manner as hereinafter set forth, of an electric light having the bulb thereof provided with an opaque portion 01 such design as to materially increase the efliciency of the light when the same is placed in proper position in a reflector, the object being to cut off the spot of light ordinarily projected from a reflecting surface such as the reflector of an automobile headlight, and also to cut off some of the upwardly directed rays of light which are ordinarily cast from the lower portion of the headlight reflecting surface.

The invention will be best understood from a considerationof the following detailed description taken in connection with the accompanying drawing forming a part of this specification, with the understanding, however, that the invention is not confined to any strict conformity with the showing of the drawing but may be changed or modified so long as such changes or modifications mark no material departure from the salient features of the invention as expressed in the appended claim.

In the drawing Figure 1 shows an electric light bulb showing the contour of the opaque portion, from the side.

Figure 2 shows the underside of theopaque portion of the bulb and,

Figure 3 shows the bulb in front elevation showing the manner in which the opaque portion covers the front end of the bulb.

Referring now'to the drawing in detail,

40 the numeral 1 indicates the base of an electric bulb, the bulb proper thereof being indicated by the numeral 2. As is of course well known the bulb 2 is ordinarily formed of transparent glass so that when the bulb is in use the light rays are projected therefrom in all directions, without interruption.

When such clear glass bulbs are used in connection with the parabolic reflector of an automobile headlight, it is well known that the light rays are cast from the reflector from the lowervportion upwardly and from the upper portion downwardly and from the central portion of the reflector is cast a beam or spot of light which is partlcularly disconcerting to persons facing the reflector. It IS 1926. Serial No. 127,431.

the object of this invention to provide a bulb which will prevent the casting of this spot of li ht and which will also prevent the upwar projection of some of the light rays from the lower portion of the reflector.

The bulb 2 has the forward end thereof made opaque as indicated at 3, by etching or by the application of a substance thereto such as a heat'resisting paint or enamel. As is shown this portion 3 is substantially cir-. cular and covers almost the entire end of the bulb, there being a narrow light emitting portion surrounding the opaque portion 3, when looking at the bulb from the front thereof as in Figure 3. I

The substantially circular opaque portion 3 at the forward end of the bulb extends downwardly, when the bulb is arranged in the horizontal position in which it would be placed in a headlight, passing along the lowermost side of the bulb2 and gradually decreasing in width, as shown.

The opaque portion extends rearwardly along the underside of. the bulb to the base 1 and is of gradually decreasing width, the side edges of the opaque strip 5 being relatively straight as shown. The edge 6 of the forward opaque portion 3 is substantially straight when the bulb is viewed from the side as in Figure 1, and the edges 4 of the strip 5 and of the forward opaque portion 3 are connected by the curved edge 7 From this description of the manner in which the opaque surface is formed over the bulb 2, it will be readily seen, that viewing the bulb from the front, no central beam of light will be projected therefrom and also that certain of the light rays will be revented from passing downwardly to the ower portion of a reflector in which the bulb is placed thereby preventing or cutting off dangerous beams of light.

Having thus described my invention what I claim is In an electric bulb of the character described, a body having a non-light emitting portion lying concentrically substantially over the entire forward end of the bulb and extending longitudinally of the wall of said body in a direction toward its rear end, said portion being gradually tapered from the forward to the rear end of the body.

In testimony whereof, I aflix my signature hereto. 

